As is well known to those skilled in the art, an oxychlorination process involves the reaction between a hydrocarbon, oxygen and a chlorination agent, usually hydrogen chloride, to produce chlorinated hydrocarbons.
A typical process for the oxychlorination of ethane is the modified Deacon type chlorination procedure in which the ethane is chlorinated, at elevated temperatures, with hydrogen chloride and an oxygen containing gas, such as air or elemental oxygen, in the presence of a metal halide catalyst such, for example, as cupric chloride/aluminum oxide. In this process, the first step in the reaction is believed to involve the oxidation of the hydrogen chloride in the presence of the catalyst so as to form chlorine and water whereupon, in the second step of the reaction, the chlorine which is liberated from the hydrogen chloride reacts with the ethane which is present in the feed gas so as to form chlorinated hydrocarbons, of which ethyl chloride is a principal component, and additional hydrogen chloride. The hydrogen chloride produced by this second step in the reaction is then oxidized as part of the first step in the reaction process and the resulting chlorine reacts with additional ethane.
In a modification of the above described ethane oxychlorination process, elemental chlorine is used as the chlorination agent and the hydrogen chloride is generated by the chlorination of the ethane and fed, together with the elemental chlorine, to the catalytic reaction zone. Thus, free chlorine, an oxygen containing gas, such as air or oxygen, and ethane are brought into contact with a metal halide catalyst maintained at elevated temperatures. The chlorine reacts with the ethane so as to produce hydrogen chloride and chlorinated derivatives of the ethane of which ethyl chloride is the major component. The chlorine content of the hydrogen chloride which is produced in this manner is then utilized to achieve additional chlorination of the ethane feed by means of a standard Deacon type reaction, as described hereinabove, in which the hydrogen chloride is oxidized to form water and elemental chlorine.